High rate discharge (HRD) valve opening mechanism for a fire and explosion protection

ABSTRACT

A valve actuation mechanism has a plurality of links. Each link has a proximal end and distal end, and the links are disposed adjacent a valve member. The actuation mechanism also has at least one roller connected to the distal ends of at least two links. The roller contacts a surface of the valve member. In addition, at least one pivot for each link is present in the valve, wherein each pivot is positioned on the proximal end of each of the plurality of links.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority as a divisional application under 35U.S.C. §121 of earlier filed application Ser. No. 13/314,852, entitled“HIGH RATE DISCHARGE (HRD) VALVE OPENING MECHANISM FOR A FIRE ANDEXPLOSION PROTECTION” and filed on Dec. 8, 2011, which is herebyincorporated by reference.

BACKGROUND

This invention relates to a method of and apparatus for the discharge ofone or more fire extinguishing agent(s). More particularly, theinvention relates to a valve opening mechanism suited to the rapiddischarge of fire extinguishing agent(s) and other high mass flowapplications.

The invention refers to an apparatus used to rapidly disperseextinguishing agents within a confined space such as the crewcompartment of a military vehicle following a fire or explosion event.These automatic fire extinguishing systems (AFES) are deployed after theevent has been detected, typically using high speed infrared (IR) and/orultra violet (UV) sensors. The systems comprise a cylinder filled withextinguishing agent, a fast acting valve and nozzle which enables rapidand efficient deployment of agent throughout the vehicle.

The rapid discharge of a fire extinguishing agent into confined areas ofvehicles subsequent to an incident (such as a fuel explosion) is knownto suppress the adverse effects experienced by the personnel within thevehicle to survivable levels. Some of the criteria used to determine asurvivable event include extinguishing the flame and preventingre-flashing; a reduction in temperature to prevent greater than seconddegree burns; and the realization of safe levels (i.e. levels up towhich personnel can continue to carry out their duties) of overpressure,acid gas, oxygen and concentration of fire extinguishing agent withinthe vehicle.

A known apparatus for fire extinguishing in such circumstances comprisesa generally cylindrical canister which contains a fire extinguishingagent which is pressurized by a gas such as nitrogen. The fireextinguishant agent must be applied rapidly. The outlet for theextinguishant from the canister is typically positioned at the base ofthe cylinder. A high rate discharge (HRD) valve is operated to allow thedischarge of the extinguishing agent. The opening of the valve allowsthe nitrogen to expand, pushing the extinguishant between it and thevalve out through the valve. The orientation of the canister and thelocation of the outlet in the cylinder allow a high proportion of theextinguishing agent to be discharged rapidly (because the extinguishingagent will be pushed out of the outlet by the nitrogen adjacent theextinguishing agent).

Existing HRD valves, following an actuation, are normally re-furbishedaway from the vehicle prior to re-use. In certain field conditions thiscauses logistical and cost issues as both the return of used suppressorsand the supply of new or re-furbished hardware to the vehicle isrequired. In an attempt to minimize this inconvenience, a new design ofthe HRD valve is being disclosed that can, if required, be disposed ofrather than re-furbished. The proposed modified valve may incorporatesome common features to the existing valve such as outlet and pressuregauge locations but maintain system efficacy against the fire/explosionchallenges.

SUMMARY

In one embodiment, a valve actuation mechanism has a plurality of links.Each link has a proximal end and distal end, and the links are disposedadjacent a valve member. The actuation mechanism also has at least oneroller connected to the distal ends of at least two links. The rollercontacts a surface of the valve member. In addition, at least one pivotfor each link is present in the valve, wherein each pivot is positionedon the proximal end of each of the plurality of links.

In another embodiment, a high speed valve has a valve body having a flowpassage therethrough and a poppet disposed within the valve body. Thepoppet is movable between a first position in which the poppet blocksthe flow passage and a second position. The poppet containing a pistonconnected to a stem at a proximal end of the stem. The valve also has apivotal link actuation mechanism adjacent a distal end of the stem.

In yet another embodiment, a fire suppression system has a pressurecontainer for holding a fire suppression material that is connected to ahigh speed valve. The high speed valve has a valve body having a flowpassage therethrough and a poppet disposed within the valve body. Thepoppet is movable between a first position in which the poppet blocksthe flow passage and a second position. The poppet containing a pistonconnected to a stem at a proximal end of the stem. The valve also has apivotal link actuation mechanism adjacent a distal end of the stem. Thesystem also has a conduit connected to the flow passage of the valve, anozzle for dispersing the fire suppression material upon opening of thehigh speed valve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of prior art apparatus for the discharge ofa fire extinguishing agent.

FIG. 2 is a perspective view of a prior art high rate discharge (HRD)valve.

FIG. 3A is a cross-sectional view of the prior art HRD valve in theclosed position.

FIG. 3B is a cross-sectional view of the prior art HRD valve in the openposition.

FIG. 4 is a perspective view of an HRD valve with a pivotal-linkactuation mechanism.

FIG. 5 is a cross-sectional view of the HRD valve with pivotal-linkactuation mechanism.

FIG. 6 is an elevation view of the pivotal link actuation mechanism.

FIG. 7 is a perspective view of another embodiment of an HRD valve.

FIG. 8 is another perspective view of the HRD valve.

FIG. 9 is an elevation view of another embodiment of the pivotal-linkactuation mechanism.

FIG. 10 is a cross-sectional view of yet another embodiment of the HRDvalve.

DETAILED DESCRIPTION

A prior art apparatus 11 for the discharge of a fire extinguishing agentis shown in FIGS. 1-3B. Referring to FIG. 1, apparatus 11 comprises agenerally cylindrical canister 12 and a releasing mechanism 13, such asa valve assembly 14 including high rate discharge (HRD) valve 15. Thereleasing mechanism 13 is opened by solenoid actuator 16. Apredetermined mass of fire extinguishing agent is added to the canister12, which is then super-pressurized with nitrogen. Canister 12 is madefrom steel or a similarly high strength, rigid material to contain thepressurized extinguishing agent.

When the releasing mechanism 13 is opened the fire extinguishing agentdischarges from the canister 12 in a fraction of a second. Canister 12is usually fitted vertically (that is with its longitudinal axisextending vertically), or as close to vertical as possible, within anenclosed or confined area of a vehicle. In order for the fireextinguishing agent to be distributed homogenously within the confinedarea without adversely impacting the personnel or equipment containedtherein, an outlet nozzle 17 needs to be extended to the highest pointthereof, such as where the walls meet the roof. This is achieved in theapparatus 11 by connecting the nozzle 17 to the releasing mechanism 13via conduit 18, such an appropriate length of hose or pipe.

The vertical orientation of the canister 12 allows releasing mechanism13 at the outlet of canister 12 to be located at the lowest point. Inone embodiment, the fire extinguishant lies at the base of canister 12(due to its relatively high density), with the nitrogen or a similarfluid pressurizing the space above. When the releasing mechanism 13 isopened, the pressurizing fluid expands and rapidly forces theextinguishant through HRD valve 15, along conduit 18 and out of nozzle17.

When the fire extinguishing agent is super-pressurized by pressurizedfluid within canister 12, a proportion of the fluid dissolves into thefire extinguishant. When HRD valve 15 is operated to deploy the fireextinguishant agent, the rapid expansion of gas dissolved within thefire extinguishing agent causes turbulence within canister 12, whichforms a two phase mixture of liquid extinguishing agent and pressurizingfluid, and a foam or mousse is formed.

FIG. 2 is a perspective view of a prior art high rate discharge (HRD)valve 15 of valve assembly 14 that also includes release mechanism 13and solenoid 16. Valve 15 contains hollow body 20 with an elongate boreon a vertical axis that terminates with an opening that forms inlet 22.Hollow body 20 has an enlarged central cavity (as seen in FIGS. 3A and3B) that communicates laterally with discharge outlet 24. The body ofvalve 15 is constructed from a metal alloy, or similarly rigid material.Valve 15 also contains mechanical override 26, as well as solenoid 16for actuating the internal regulating mechanisms of valve 15.

FIGS. 3A and 3B illustrate the internal workings of valve 15. The mainoperating and regulating mechanism of valve 15 is poppet 30. Poppet 30is used to close the entrance to an opening in the body of valve 15.Poppet 30 contains a piston 31 at proximate end 34, connected to stem 35that terminates at distal end 36 adjacent actuating mechanisms, such asmechanical override release mechanism 13 and solenoid 16. Poppet 30 isconstructed from a material the same as or similar to that of body 20 ofvalve 15. Poppet 30 and stem 35 may be of various geometries, such ascircular, oval, or polygonal in cross section so long as they matchcorresponding valve structures, such as the bore opening of inlet 22. Inone embodiment, poppet 30 is generally cylindrical, as is stem 35 thatis centrally aligned with poppet 30.

One or more annular grooves in piston 31 contain o-rings 32 whichcompress against the bore of valve 15, providing a seal. O-rings 32 arefabricated from rubber, or a similar elastomeric polymer capable ofcreating an air-tight seal between poppet 30 and body 20. Pressureinside canister 12 (illustrated in FIG. 1) pushes against proximate end34 of poppet 30, forcing poppet 30 upward while constraining seals 32against inlet 22 and canister 12. Once poppet 30 is released,pressurized fluid contained inside canister 12 moves poppet 30 allowingthe fluid to escape through outlet 24. An elastomeric bumper 38 quietsthe operation and prevents damage to poppet 30 and valve body 20.Following the actuation of the valve via the release mechanism,typically a collet connected to solenoid 16 with mechanical override 26consisting of a linkage assembly, poppet 30 slides to the open positionallowing pressurized fluid, such as a fire extinguishant, to flow out ofoutlet 24. The use of this common valve body 20 and poppet 30arrangement allows for high mass flow rates through the valve 15.

FIGS. 4 to 10 illustrate novel release mechanisms for valve 15. FIG. 4is a perspective view of HRD valve 15 with a pivotal-link actuationmechanism 40, and FIG. 5 is a cross-sectional view of HRD valve 15 withpivotal-link actuation mechanism 40. Valve 15 contains body 20 with ahollow cavity creating communication between inlet 22 and outlet 24,poppet 30 with piston 31, o-rings 32, and stem 35, and bumper 38 thathave all been previously described. Poppet 30 is restrained by pivotallink actuation mechanism 40, which has links 42 a-42 d, rollers 44 a and44 b, and pivots 46 a-46 b. In the embodiment illustrated, links areflat plate structures with rounded tops and bottoms, and are made frommetal. The top and bottom of links 42 contain holes that allow for theattachment of rollers 44 between adjacent links, as well as attachmentto pivots 46. Rollers 44 are cylindrical metal rods that extend betweenadjacent links and are capable of rotation therebetween, forming what isa structure similar to a roller chain. Pivots 46 are short pieced ofmetal rods attached to body 20 of valve 15. In alternate embodiments,pivots may be machined directly into body 20 during manufacture of valve15. In the closed position, poppet 30 is constrained vertically by thesets of pivoting links 42 and rollers 44 that contact top surface 48 ofstem 35. Links 42 also contact each other in the over-center position.Gap 49 in body 20 of valve 15 allows for the movement of pivotal-linkactuation mechanism 40. Gap 49 is a cutout in body 20 that will vary indimension with differing embodiments, and will be dependent on spacerequirements for actuation of pivotal-link actuation mechanism 40.

For the links to rotate and allow the roller to roll off the edge of thestem 35 (and thus allow movement of poppet 30), there is a slightvertical displacement given by Y=(r/COS θ)−r. The mechanical advantageis extremely high at a small angle, so a small horizontal force canovercome a very high vertical force. Besides the forces required to movepoppet 30, the horizontal force applied to rollers 44 will also have toovercome the drag created by the force against the roller axle, and asmall amount of force from pivots 46. FIG. 6 illustrates pivotal linkactuation mechanism 40 in operation where the links have been separated,i.e. pivoted, to a point close to allow stem 35 vertical motion.

FIG. 7 is a perspective view of another embodiment of pivotal linkactuation mechanism 40 for HRD valve 15. As previously described, poppet30 is restrained by pivotal link actuation mechanism 40, which has links42, rollers 44, and pivots 46 (not shown in this view). Stem 35 containswedge 50 on the exterior of distal end 36, and an electrically actuatedrod 52 contained within the interior that acts as a protractor pin. Inthe embodiment illustrated, links 46 are pushed apart from the center ofstem 35 using wedge 50, which is a taper on the pin of stem 35. Wedge50, along with rod 52 and the electric initiator 54, are mounted belowrollers 44 within the body of the poppet 30. On actuation, the electricprotractor forces rod 52 out. Typical forces from such devices vary from1000 N to around 5000 N, though higher and lower values can be provided.In the embodiment illustrated, wedge 50 has two 20° slopes. In analternate embodiment, distal end 36 of stem 35 is generally conical inshape creating approximately a 20° slope for a portion of stem 35. Whencombined with the force and linear movement from rod 52, rollers 44 arepushed over the vertical edge of stem 35, which allows poppet 30 to moveto the open position. The angle of wedge 50 could be optimized dependingon the force and linear motion provided by the actuation device used toopen valve 15. This type of operation would work just as well if wedge50 was used to force links 42 open from the top, but this would alsoincrease the overall space claim of valve 15.

FIG. 8 is a perspective view of another embodiment of HRD valve 15. Dueto normal manufacturing tolerances, one of the two links 42 a or 42 bwill likely be slightly shorter than the other, so the shorter link willtake the majority of the load. Poppet 30 can tip slightly to align withthe mismatched links, but the tipping may cause additional drag, as wellas cause uneven pressure on o-rings 32. The embodiment of illustrated inFIG. 8 features a moving connection mount rocker 56 that carries bothlinks 42 a and 42 b. Rocker 56 is constrained vertically by backingplate 58. Tapers on both sides of backing plate 58 allow the connectioncontaining rocker 56 to rotate or swing slightly to accommodatemismatched links 42 a and 42 b—assuring that each link carries equalloads.

FIG. 9 is an elevation view of another embodiment of pivotal linkactuation mechanism 40. In the embodiment illustrated, cut outs 60 a and60 b are located just below rollers 46 a and 46 b on both links 42 a and42 b. In the closed position, flat areas 62 a and 62 b of cut outs 60 aand 60 b are used to hold poppet 30 in place. A protractor 64 is mountedhorizontally within the valve assembly, which on actuation pushes thelinks 42 apart to the over vertical position and allows poppet 30 to bedisplaces to open valve 15. Angled portions 66 a and 66 b of cut outs 60a and 60 b allow for stem 35 to clear pivotal link actuation mechanism40 with minimal rotation of links 46 about pivot points 44. Protractor64 may be an electronically actuated pyrotechnic device, such as aMetron™ actuator. In one embodiment, a groove 65 is contained within oneof the links to allow contact with the actuation mechanism, such as arod or actuation pin, from protractor 64. The horizontal movement ofprotractor 64 along with cut outs 62 in links 46 provides a more compactdesign in terms of the overall valve space envelope required for pivotallink actuation mechanism 40.

FIG. 10 is a cross-sectional view of yet another embodiment of the HRDvalve 15 with pivotal link actuation mechanism 40. As previouslydescribed, poppet 30 is restrained by pivotal link actuation mechanism40, which has links 42, rollers 44, and pivots 46. Stem 35 containswedge 50 on extending from the top of distal end 36, which is connectedto pressure actuated rod 72 contained within interior bore 74 of stem35. Seals 76 extend around the base portion of actuation rod 72 tocreate an airtight connection between bore 74 and rod 72. Wedge 50contains a different geometry than that previously described, and haspressure inlet 70 attached to the top thereof. In the embodiment shownin FIG. 10, pressure is communicated into wedge 50 assembly, theresultant force of which is used to drive wedge 50 up into the linkageassembly. The pressure could be communicated via the extinguisher itself(e.g. with a solenoid valve in line, or other actuation device), or viaa separate pressure vessel or canister. An external pressurized canistercould be used to operate one or several extinguishers containing theaforementioned and described pivotal link actuation mechanism 40illustrated in FIG. 10. Optionally, a spring mechanism to store therequired energy to operate wedge 50 could be provided that would pushrod 72 upward to release poppet 30.

While the invention has been described with reference to an exemplaryembodiment(s), it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed, but that theinvention will include all embodiments falling within the scope of theappended claims.

The invention claimed is:
 1. A valve actuation mechanism, comprising: aplurality of links, each link with a proximal end and distal end, thelinks disposed adjacent a valve member, wherein at least one of theplurality of links comprises: a generally horizontal portion thatcontacts a surface of the valve member; and an angled portion adjacentthe horizontal portion; wherein at least one of the plurality of linkscontains a groove adjacent the distal end; a roller connected to thedistal ends of two adjacent links of the plurality of links; a pivot foreach link present in the valve actuation mechanism, wherein each pivotis positioned on the proximal end of each of the plurality of links; andan actuation mechanism configured to contact the groove when in a firstposition.
 2. The valve actuation mechanism of claim 1, wherein thesurface of the valve member is a flat surface generally parallel to thegenerally horizontal portion of at least one of the plurality of links.3. The valve actuation mechanism of claim 1, wherein the actuatingmechanism comprises an electronic protractor.
 4. The valve actuationmechanism of claim 1, wherein the actuating mechanism comprises anelectronically actuated pyrotechnic device.
 5. The valve actuationmechanism of claim 4, wherein the electronically actuated pyrotechnicdevice is mounted generally horizontal to the valve member and containsa rod that contacts the groove.
 6. The valve actuation mechanism ofclaim 1, further comprising: a rocker connected between adjacent linksand pivots; and a tapered backing plate connected to the rocker.
 7. Avalve, comprising: a valve body having a flow passage therethrough; apoppet containing a piston connected to a stem at a proximal end of thestem disposed within the valve body, the poppet movable between a firstposition in which the poppet blocks the flow passage and a secondposition in which the poppet opens access to the flow passage; and apivotal link actuation mechanism adjacent a distal end of the stemcomprising: a plurality of links, each link with a proximal end anddistal end, the links disposed adjacent the poppet, wherein at least oneof the plurality of links comprises: a generally horizontal portion thatcontacts a surface of the poppet; and an angled portion adjacent thehorizontal portion; wherein at least one of the plurality of linkscontains a groove adjacent the distal end; a roller connected to thedistal ends of two adjacent links of the plurality of links; a pivot foreach link present in the valve, wherein each pivot is positioned on theproximal end of each of the plurality of links; and an actuationmechanism configured to contact the groove when in a first position. 8.The valve of claim 7, wherein the surface of the poppet is a flatsurface generally parallel to the generally horizontal portion of eachof the at least one of the plurality of links.
 9. The valve of claim 7,wherein the actuating mechanism comprises an electronic protractor. 10.The valve of claim 7, wherein the actuating mechanism comprises anelectronically actuated pyrotechnic device.
 11. The valve of claim 10,wherein the electronically actuated pyrotechnic device is mountedgenerally horizontal to the poppet and contains a rod that contacts thegroove.
 12. The valve of claim 7, further comprising: a rocker connectedbetween adjacent links and pivots; and a tapered backing plate connectedto the rocker.
 13. A fire suppression system, the system comprising: apressure container for holding a fire suppression material; a high speedvalve connected to the container comprising: a valve body having a flowpassage therethrough; a poppet disposed within the valve body, thepoppet movable between a first position in which the poppet blocks theflow passage and a second position in which the poppet opens the flowpassage, the poppet containing a piston connected to a stem at aproximal end of the stem; and a pivotal link actuation mechanismadjacent a distal end of the stem comprising: a plurality of links, eachlink with a proximal end and distal end, the links disposed adjacent thepoppet, wherein at least one of the plurality of links comprises: agenerally horizontal portion that contacts a surface of the poppet; andan angled portion adjacent the horizontal portion; a conduit connectedto the flow passage of the high speed valve; and a nozzle configured todisperse the fire suppression material upon opening of the high speedvalve.